DAKAR, Senegal — Congo will open three treatment centers for the Ebola virus in the eastern Ituri province following an outbreak of a variant that has no approved therapeutics or vaccines, as the World Health Organization sent a team of experts and supplies to help combat the spread of the disease.

“We know that the hospitals are already under stress because of the patients,” said Samuel Roger Kamba, the Congolese health minister, during a visit to Bunia, Ituri’s capital and largest city, on Sunday. “But we are preparing to have treatment centers at all three sites in order to be able to expand our capabilities.”

The WHO on Sunday declared the Ebola disease outbreak a public health emergency of international concern. As of Monday, there were over 390 suspected cases and 105 deaths in Congo, according to Congo’s Health Cluster, and two deaths in neighboring Uganda.

Delayed response

The first person died from the virus on April 24 in Bunia, Kamba told reporters in Kinshasa on Saturday.

“The body was repatriated to the Mongbwalu health zone,” Kamba said. “It was the return of this body to the Mongbwalu health zone — a mining area with a large population — that caused the Ebola outbreak to escalate.”

The director of Africa Centers for Disease Control told reporters on Saturday that another person fell ill on April 26, and that samples were sent to Kinshasa for testing.

On May 5, WHO was alerted of about 50 deaths in Mongbwalu, including four health workers who died within four days, which prompted investigations, the Africa CDC director said. The first case was confirmed on May 14.

The delay was partly due to the fact that the samples of the Bunia cases were initially tested for the previous strain, Zaire, Congolese officials said.

“The province analyzed the Zaire strain, for which they have the expertise, and it came back negative,” said Dr. Richard Kitenge, the Health Ministry Incident Manager for Ebola. “So, for the province, Ebola was negative.”

Although the outbreak is centered in Congo’s Ituri, cases have been reported in the capital, Kinshasa, and in Goma, the largest city in the country’s east.

Aid groups Medecins Sans Frontieres and the International Rescue Committee said on Monday they have dispatched teams responding to the outbreak.

CBS says 6 Americans exposed to virus

CBS News reported on Sunday that at least six Americans have been exposed to the Ebola virus in Congo, citing anonymous sources in international aid organizations. The Associated Press has not been able to independently verify this information.

US health officials said Sunday the risk to Americans was low, but did not directly answer questions about whether any Americans may have been exposed to the Ebola virus in Africa.

The US Centers for Disease Control and Prevention issued travel advisories on Friday, urging Americans traveling in Congo and Uganda to avoid people who have symptoms like fever, muscle pain and rash. The CDC also said it is “putting in appropriate measures for identifying individuals with any symptoms” at ports of entry.

An unusual strain

Ebola is highly contagious and can be contracted via bodily fluids such as vomit, blood or semen. The disease it causes is rare, but severe and often fatal.

Health authorities say the current outbreak, first confirmed on Friday, is caused by the Bundibugyo virus, a rare variant of the Ebola disease that has no authorized vaccines or treatments. Although more than 20 Ebola outbreaks have taken place in Congo and Uganda since 1976, this is only the third time that the Bundibugyo virus has been detected.

The U.S. CDC says the Bundibugyo virus causes fever, headache, muscle pain, weakness, diarrhea, vomiting, stomach pain, and unexplained bleeding or bruising.

Dr. Gabriel Nsakala, a professor of public health who has been involved in past Ebola outbreak responses in Congo, said treatments for viral infections like Ebola are often directed at symptoms.

He said Congo has extensive experience managing Ebola outbreaks, but response efforts could be complicated by the unusual strain.

The Bundibugyo virus was first detected in Uganda’s Bundibugyo district during a 2007-2008 outbreak that infected 149 people and killed 37. The second time was in 2012, in an outbreak in Isiro, Congo, where 57 cases and 29 deaths were reported.

The WHO Regional Office for Africa wrote Sunday on X that a team of 35 experts from the WHO arrived in Bunia, along with 7 tons of emergency medical supplies and equipment.

The outbreak started in a remote locality already grappling with a humanitarian crisis

Mongbwalu is a high-traffic mining area in Ituri, a province in a remote eastern part of Congo, with poor road networks, and is more than 620 miles from the nation’s capital, Kinshasa.

Eastern Congo has been grappling with a humanitarian crisis even before the new outbreak was confirmed.

The agency said there’s also a risk of further spread due to intense population movement and attacks by armed groups that have killed dozens and displaced thousands in parts of Ituri in the past year.

“The outbreak is currently occurring in provinces marred by crisis, including insecurity, presence of armed actors or de facto authorities with large displacement, weak health systems and insufficient availability of services,” Congo’s Health Cluster said on Monday.

“No one really has a full understanding of how serious this crisis is,” a Bunia-based U.N. official who was not allowed to speak on the subject publicly told The Associated Press. “The extent to which it’s expanding is very much unknown.”

Staff have been asked to work from home and to avoid physical contact and crowded areas, the official said, adding that “it doesn’t feel like crisis mode yet.”

But with meetings moved online, the official said they were concerned about halting activities in a region that relies on humanitarian aid to survive. There are over 273,00 displaced people in Ituri and a total of 1.9 million people in need, according to the U.N.

Health officials are in ‘panic mode’ due to a lack of medicines and vaccines

The WHO’s emergency declaration is meant to spur donor agencies and countries into action. By the agency’s standards, it shows the event is serious, there is a risk of international spread and it requires a coordinated international response.

Kaseya, director-general of the Africa CDC, told Sky News on Sunday that he is in “panic mode” due to a lack of medicines and vaccines as deaths rise, but that some candidate treatments were anticipated in the coming weeks.

Rwanda closed its land border with Congo on Sunday, the U.S. State Department said on social media. AP reporters tried to cross the border on Sunday and Monday morning, but were informed it was closed except for holders of international flight tickets. Rwandan authorities have not replied to a request for comment.